Blender animation constraint "Track to" not working for soft bodies
Assign a vertex group.
Further to @moonboots answer, Since the soft body modifier alters the mesh but not the origin can select all or any vertices of the soft body mesh and assign to a vertex group.
Soft body mesh in  edit mode, select verts, make a new vertex group, assign to group.
In the camera's track to constraint, choose the vertex group as sub-target.

Tracking to &quot;Group&quot; vertex group (All) of the icosphere
The same method can be used to track to any modified mesh.